The two options are according to https://wiki.archlinux.org/index.php/Intel#X_freeze.2Fcrash_with_intel_driverHowever, the "Shadow" option keeps killing X or simply preventing X from starting when an external monitor is connected.

I was running Fedora 15 64bit on the laptop, but the system hanged up frequently (more than daily) and needed hard reboot. That forced me to switch to PUIAS about one week ago. I hope this info can be useful since SL 6.1 uses the same kernel as PUIAS.

We are using Intel SandyBridge Video drivers and the issues we had in version 6 has been resolved in Version 6.1. Thanks to intel and to RHEL...and ofcourse to Scientific Linux too for the timely release of 6.1

[QUOTE=guotatofu,Jul 25 2011, 03:35 PM]I am running PUIAS 6.1 on a Lenovo Thinkpad T520 with Intel HD3000. It appears that it is necessary to specify the "i915.modeset=1" option in grub.conf to make X work.